Content deleted Content added
m Disambiguating links to Pyroclastic (link changed to Pyroclastic rock) using DisamAssist. |
Zoingeroing (talk | contribs) moved wikilink to feldspar to top of page |
||
Line 46:
}}
'''Orthoclase,''' or '''orthoclase [[feldspar]]''' ([[endmember]] formula [[potassium|K]][[aluminium|Al]][[silicon|Si]]<sub>3</sub>[[oxygen|O]]<sub>8</sub>), is an important [[Silicate minerals#Tectosilicates|tectosilicate]] [[mineral]] which forms [[igneous rock]]. The name is from the [[Ancient Greek]] for "straight fracture", because its two cleavage planes are at right angles to each other. It is a type of '''potassium feldspar''', also known as '''K-feldspar'''. The gem known as [[Moonstone (gemstone)|moonstone]] (see below) is largely composed of orthoclase.
==Formation and subtypes==
Line 61:
==Uses==
Together with the other potassium
Some intergrowths of orthoclase and [[albite]] have an attractive pale [[luster (mineralogy)|luster]] and are called [[Moonstone (gemstone)|moonstone]] when used in jewellery. Most moonstones are translucent and white, although grey and peach-colored varieties also occur. In gemology, their luster is called [[adularescence]] and is typically described as creamy or silvery white with a "billowy" quality. It is the [[state gem]] of [[Florida]].
| |||